Hangzhou: Leaders of the world's biggest powers met Sunday to try to revive the sluggish world economy, with their host Chinese President Xi Jinping urging them to avoid "empty talk".
Xi welcomed each president and prime minister to the Group of 20 summit with a handshake, and had an extended clasp with Barack Obama as both men smiled, despite protocol stumbles around the US leader's visit.
In a circular conference hall in Hangzhou — the scenic eastern city left deserted by a vast security operation — Xi told them the G20 "should work with real action with no empty talk".
China is hoping a successful meeting will portray it as an assured, powerful nation ready to assume a role on the international stage that befits its status as the world's second-largest economy.
Authorities shuttered thousands of factories to try to ensure clear skies, and encouraged residents to leave town on free holidays, as well as detaining dozens of dissidents to prevent any hint of unrest.
The G20 brings together representatives of 85 percent of the world's GDP and two-thirds of its population.
But experts expect the gathering to be short on substance, with no acute crisis pushing leaders to defy rising populist sentiment and take difficult steps such as liberalising trade to address the world's most pressing issues.
Even so it was preceded by a flurry of diplomatic activity in China on issues ranging from climate change and the war in Syria to international trade.
The US and China Saturday ratified the Paris climate accord, a crucial step towards bringing into force the pact against global warming.
UN chief Ban Ki-moon, who personally received the ratification documents from Xi and Obama, applauded them Sunday for "making this historic step" and urged other G20 leaders to follow suit.
'Around the clock'
On Sunday the US said it was close to a deal with Russia on stemming the violence in Syria's brutal civil war, with President Barack Obama saying negotiators were "working around the clock".
Moscow and Washington support opposite sides in the conflict, which erupted in March 2011 after President Bashar al-Assad unleashed a brutal crackdown against a pro-democracy revolt.
Successive rounds of international negotiations have failed to end a conflict that has left more than 290,000 people dead and forced millions to flee, a key contributor to migrant flows into Europe.
"It is a very complicated piece of business," Obama told reporters.
EU President Donald Tusk said Europe was "close to limits" on its ability to accept new waves of refugees and urged the broader international community to shoulder its share of the burden.
The issue has become a political hot potato for European leaders in the face of Islamist terror attacks and rising anti-globalisation sentiment driving public resentment of immigration.
Pictures of a drowned three-year-old Syrian boy lying on a Greek beach briefly changed the discourse last year, with Germany throwing open its borders, but a major backlash swiftly followed.
Ahead of the summit, Canadian Prime Minister Justin Trudeau warned against "rampant" protectionism and nationalism, saying that "building walls" was not the solution."
The talks are being held in the wake of Britain's vote to leave the European Union, which leaves it with the task of renegotiating access to the markets of the rest of the world, as well as those of the group it is leaving.
It is a huge job for the world's fifth-biggest economy, and Australian Prime Minister Malcolm Turnbull said Canberra had "got things moving towards having a free trade agreement with the UK".
But European Commission chief Jean-Claude Juncker said he opposes such talks while Britain remains part of the EU, insisting they were an "exclusive matter" for the bloc on behalf of its members and "we are sticking to it".
With the world in town, Beijing is keen to avoid discussion about the South China Sea — where it has built artificial islands and facilities including airstrips on reefs and outcrops in disputed waters — that could cloud the proceedings.
But there were suggestions of a testy exchange between Xi and Obama Saturday over a ruling by a UN-backed tribunal which found there was no legal basis for Beijing's claims to the waterway.
The White House said the two leaders had a "candid exchange" on the issue, while Xinhua said Xi urged the Washington to "play a constructive role" in the area.
China craves a polished summit but there were more wrinkles Saturday when a shouting match broke out over access for reporters travelling with Obama as Air Force One arrived on the tarmac.
"This is our country!" a Chinese official, in a dark suit, shouted at a White House staffer. "This is our airport!"
Obama took the fracas in his stride on Sunday, saying that although the US insists on press access and does not "leave our values and ideals behind", the travelling White House juggernaut could be intimidating.
"I think this time... the seams are showing a little more than usual in terms of some of the negotiations and jostling that takes place behind the scenes," he told a press conference.